Immunohistochemical localization of gamma-aminobutyric acid- and aspartate-containing neurons in the rat deep cerebellar nuclei.

The immunohistochemical localization of gamma-aminobutyric acid (GABA)- and aspartate-containing neurons was evidenced in the rat deep cerebellar nuclei, using purified antisera to GABA and aspartate, respectively. Most GABA-containing neurons had small cell bodies and were scattered unevenly throughout the deep cerebellar nuclei. The medial cerebellar nucleus had a few GABA-containing cell bodies and interpositus and lateral nuclei contained many GABA-containing cell bodies. GABA-containing terminals were distributed throughout the nuclei. A large number of various-sized aspartate-containing cells were present in the deep cerebellar nuclei and most of these cells were large or medium-size. Aspartate-containing cells in the medial, interpositus and lateral nucleus were surrounded by GABA-like immunoreactive terminals, thereby suggesting the modulation of aspartate-containing neurons by GABA-ergic fibers from Purkinje cells.